OPERATING INSTRUCTIONS FOR AERIOLA SR.
Contents
1. Do not try to burn too brightly as this materially reduces the life of the filament No 13 Rotate tuning handle slowly over the scale meanwhile listening until sound is heard in the telephone receivers Adjust to best position then increase Tickler 11 until maximum strength of signal is obtained If tickler is turned too far toward maximum position signals will lose their natural tone and reception of telephone signals may become difficult Note This terminal is also connected to terminal G of the protective device Complete Aeriola Sr Broadcasting Receiver Model RF 190 500 Meters with One Aeri otron WD 11 D Vacuum Tube One Filament Dry Cell One Plate Dry Battery Head Telephone Receivers Antenna Equipment and Full Instructions 75 90 Aeriola Sr Broadcasting Receiver Model RF As Above Less Batteries and Antenn Equipment Dimensions 7 in x 81 4 in x 714 in ee ee eee eee eee enw eee eeneeee 65 00 Weights Net 6 tbs Shipping 12 fbs with Antenna Equipment and Batteries 25 Ibs NOTE For Prices of other Complete Receiver Combinations see page 35 8 Why Is Everything So Difficult to Use I Everything that can be invented has been invented Charles H Duell Commissioner U S Office of Patents 1899 We are fond of believing that today s world of technology is special that the rapid pace of change the fights among companies in the battle for2. RADIO CORPORATION OF AMERICA OPERATING INSTRUCTIONS FOR AERIOLA SR No 7 Connect to posi tive center terminal of the single 1 5 volt dry cell No 8 Connect to nega tive outside termi nal of the single 1 5 volt dry cell and neg ative terminal of 22 5 volt plate bat tery No 9 Connect to posi tive terminal marked of 22 5 volt plate battery No 10 Insert Aeriotron Vacuum tube in re ceptacle provided Note that the four holes in base which re ceive prongs of tube are not all alike one being larger than the rest thus permitting insertion of tube in but one way Be sure prongs register with holes and then press Text numbers correspond with above diagram in firmly Numbers Corresponding to Diagram No J First refer to accompanying sketch then erect antenna and place protective device in position as described on page 56 No 2 Connect a wire leading from terminal marked R on protective device to binding post indicated by arrow for stations below 350 meters No 3 For stations between 350 and 500 meters connect the above wire to this post No 4 Connect this post with terminal G of protective device No 5 Connect telephone receivers to these two posts No 6 Turn rheostat as far as it will go to ward tail of arrow No 11 Place Tickler pointer at zero point of scale No 12 Turn rheostat 6 toward point of arrow until vacuum tube shows dull red
3. Every so often it will be wonderful Every so often it will be a nightmare come true Complexity and Difficulty There are two faces to the complexity of a device one internal to the machinery the other external to the world and to the user The com plexity that concerns me is the second kind the external complexity that determines how easy or difficult the device is to use To distinguish between these two meanings of complexity let me use complexity to refer to the internal mechanisms of the device and difficulty to refer to the factors that affect ease of use Along with advances in technology come the dreaded curses of tech nology difficulty in operation and diminished control over our lives Technology can be confusing maddening infuriating Technology is its own master It has its own requirements and own rules of operation The complexity difficulty and demands of technology have long been a source of complaint That people must conform to technology seems to be the basic premise and the notion that it is technology that should conform is a modern invention In many ways the conformance of technology wasn t even possible until recently for up until recent times it was remarkable enough that the complex mechanical and electrical devices would work at all let alone be designed to be accessible and usable by the average person This is the reason for the paradox that today s technology is largely built from a machine centere
4. and discover that with each usage they must once again ask or consult a manual then the design is faulty The goal is to let you pick up a device and use it The goal is for the device to be built for the job and be no more difficult than it needs to be Does this come at a cost Of course Among other things it means that there must be one device per activity which means a multitude of de vices It means that the devices are separate so something extra must be done if you want to combine the output of several activities All of these problematic situations can be overcome as will be shown The solutions require careful consideration of what things go together of just what is meant by an activity The solutions require a universal communication scheme so that the products of one device can be sent effortlessly to another with no more thought than if they resided on the same ma chine and considering the complexity of sharing material on today s Why Is Everything So Difficult to Use 18 machines the separate devices might even make sharing easier tha today s overloaded systems Life is full of tradeoffs with each choic being better for some things worse for others The ultimate goal is simplicity Make things fit the task make th difficulty of our tools match the difficulty of the job to be done How do we make things less difficult Sorry but the causes of today difficulties are too fundamental for simple change As we have s
5. at least so we think We sit in front of personal computers and communicate with the world In a few seconds I can do research on the history of technology by examining locations around the world Europe the United States Canada Australia Indeed I am not always sure where the information resides that I am examining and often I don t care National boundaries do not matter Today two technologies provide a powerful infrastruc ture communications and computation Put them together and it changes the face of personal interaction business education and gov ernment The financial and business sectors are breaking away from governmental boundaries and controls The world is changing in ways difficult to forecast spoon EER oe ae ee Why Is Everything So Difficult to Use 165 The Double Edged Sword of Technology The double edged sword is a technology and technology is like a dou ble edged sword It can enhance and diminish our lives I have long been a fan of technology even when I was a professor and long before I worked for the computer industry In Things That Make Us Smart I made the case for technology arguing that properly built properly deployed technology makes people smarter than we would otherwise be The problem lies in that word properly Modern day technology enslaves us as much as it empowers us The modern day culprit is the computer but I can make the point even better by looking at the te
6. follows almost inevitably from the need to improve The earliest steam engines those of Thomas New comen were extremely simple but inefficient James Watt improved the efficiency considerably but at the cost of added complexity Watt s version required extra valves parts and critical timing The piston had to fit more snugly into the cylinder so the manufacturing process had to be held to much closer tolerances The engine ran at a higher tempera ture increasing the temperature of the piston was one of the means of increasing efficiency so new lubricants and seals had to be developed that could withstand these changes The more efficient machines pro duced greater power not just in the downward direction which is all Newcomen s machine could do but in both the downward and upward cycles This increased the stress upon the parts Further efficiency re quired raising the pressure of the steam which increased the danger of explosion leading to even more complexity in the attempt to add safe guards Most technology goes through cycles of development and change in both internal and external complexity Often the very first device is simple but crude As the device undergoes the early stages of develop ment its power and efficiency improve but so does its complexity As the technology matures however simpler more effective ways of doing things are developed and the device becomes easier to use although usually by becoming m
7. learn how to use it with a minimum of effort In the ideal case no manual would be required It is unsuccessful if users simply follow in structions with no understanding they will be unable to go beyond the instructions unable to perform novel activities unable to get out of trouble Telling a coherent consistent story that is readily understood by the wide range of users is not an easy task It is a task best left to experts Task centered development human centered development conceptual model guided development These are the secrets of success There are more but these are essential starting points Why Metaphors Should Be Avoided A myth has grown up in the land that good interface design requires the development of a metaphor What metaphor shall we use to design this device I am often asked If only we would have the correct meta phor then people would find it easy to use right Wrong A metaphor is always wrong by definition After all what do we mean when we design by means of a metaphor We mean that we try to pick something else to guide the design something that already exists and that we believe the users of our devices will be familiar with The word processor is like a typewriter The display on the page is like a piece of paper The background of my computer screen is like a desktop and the files and icons that are displayed upon it are like file folders piles of paper and physical objects on my real d
8. quite different meaning than the word window in a home A real window does not have a scroll bar nor a way to change size When the window at home is shut it doesn t go away out of sight What value is added tc the computer image by thinking metaphorically For every point that the metaphor helped in understanding it confuses at all the othe points where the computer version differs from the real one Designers of the world Forget the term metaphor Go right to the heart of the problem Make a clean clear understandable conceptua model Make sure the user can learn and understand it Make all the actions consistent with that conceptual model Provide feedback anc interaction consistent with that model the better to reinforce it Forge metaphors they will only get in the way Making Computers Easy to Use Computers are general purpose devices designed to do everything Asi result they can t be optimized for any individual task Their controls ar arbitrary often limited to what can be typed on the keyboard or pointe at on the screen and clicked by the mouse There is no possibility o using the physical construction itself to present the conceptual mode of the device or of the actions since the range of functions is so large With a special purpose device everything about it can shout Here i how I work this is what I do The shape of the case the layout of th controls even the shape and form of operation o
9. supremacy and especially the story of the personal computer and tele communications revolution mark this as a special time in history Weil sort of If this is a special time in history it is because every time is special Every era is unique having its own particular quirks and foibles Today s technological revolution is sparked by the convergence of sev eral industries especially information technology communications and entertainment but even here what is happening today follows a century old historical pattern In many ways the changes during the latter part of the nineteenth century and the start of the twentieth were far more dramatic and far reaching than what we are currently witnessing at the start of the twenty first century In the early 1900s there were radical changes in lifestyles Rapid travel was not possible before now it was starting to be commonplace first by means of the train and the ocean liner then with the automobile and airplane Talking to someone at a distance had not been possible now with the invention and deployment of the tele phone it was Instant records of events both the sights via photogra phy and the sounds via the phonograph never were possible now they were Figure 8 1 The first radios were not easy to use From Radio Enters the Home New York Radio Corporation of America 1922 164 Chapter 8 Today the revolution in which we live
10. the rectangle differs from that of moving the triangle When the triangle is moved it affects the Paragraph left margin but leaves the indentation for the first line unchanged This lets me adjust the follow ing lines to be left of equal to or right of the first line When I move the rectangle both the margins for the first line and the rest of the para graph move simultaneously as if they were locked together This lets me widen or narrow the paragraph leaving the amount of indentation of Why Is Everything So Difficult to Use 179 the first line unchanged Too bad the graphical design doesn t support this conceptual model The proper graphical design would show an explicit linkage between the rectangle and both sliders One way of doing this would be to make the rectangle extend in length between the two controls If I move a control only that part of the margin is affected and the rectangle wenle grow or shrink accordingly If moved the rectangle it would move in position without changing its length thereby reinforcing the concep tual model of the operation As it is the relationship is more difficult to discover and remember than necessary This point may seem like a minuscule detail and in some respects it is But usability often lies in the details How many users of this word processor never discover the operation of the rectangle Worse ph many are confused because of what they believe to be capricious results Some
11. to that result In other words in new situations we look for familiar patterns we look for any signs that might direct us and we try to make sense of whatever happens In general people make up explanations stories of events that help us make our way through novel and complex situations until they become understandable and comfortable r E y Why Is Everything So Difficult to Use 177 The Conceptual Model The use of a good conceptual model is so fundamental to good design that I would like to discuss it here in greater detail than presented in chapter 7 What does it mean to understand how something works Do I really have to understand automobile mechanics to drive my car or to understand solid state physics and computer programming to use my computer Of course not But what I do need is a good conceptual grasp of what is going on an understanding of the different controls and alternative actions I can take and what their impact is on the device I need a story that puts together the behavior and appearance of a device in a sensible comprehensible pattern Good designers present explicit conceptual models for users If they don t users create their own mental models which are apt to be defective and lead them astray The word processor on which I am typing this chapter makes visible an excellent conceptual model for its operation There is a ruler on the top of the page with several sliding pointers What is particularly nice ab
12. was purposeful or not but surely the original design ets of these machines who had business users in mind could not have anticipated that this feature would be used in homes to screen calls to decide if the caller was somebody anyone at the receiving end wished to speak with at that moment But there is more to come Wireless telephones and pagers are increas ingly popular not just among business people but also in the home especially with teenagers Today some information technologies are so important that they get fastened to the body the watch eyeglasses and hearing aids Soon the telephone will join the watch always with us always available But what then of privacy of peace and quiet Of time to ourselves The tremendous convenience of continual access carries with it an invasion of privacy and personal space Why Is Everything So Difficult to Use 167 Will the telephone really join the watch I think it will supersede the watch and join the pacemaker The watch has become jewelry worn on the wrist as much for fashion s sake as for telling the time But a phone Why not permanently implant it in the head After all wiggle the skin just below the ear at the jawbone Feel that extra slack Just enough to make a tiny cut implant a tiny telephone put the microphone and earpiece on the bone near the ear and there you have it a telephone always available no matter where you are no matter what you are doing
13. al as were early analog computers and they were dauntingly complex and difficult It is the designer s responsibility to overcome the difficulties to pro vide coherence and understanding for the user If the designer makes the operations vague ambiguous and hidden from sight provides con trols with no obvious meaning and provides little or no feedback then the result is guaranteed to be confusing When the user lacks a clear conceptual understanding of the device the result is difficulty of use The same principles apply whether the device is mechanical or elec tronic The only difference is that many mechanical devices offer the possibility of being self explaining of having the purpose and function visible of offering continual and immediate feedback for each action Electronic information devices on the other hand by their very nature control invisible symbolic events and so the possibility of a clear con ceptual understanding is entirely up to the competence of the designer When it comes to the ability of engineers to design things so that the average user can understand them the level of competency is low in deed This is not meant to be an indictment of engineers After all they are trained in engineering not in human centered design To change things requires a design philosophy that focuses upon ease of use upon providing an appropriate conceptual model making it visible and mak ing all actions and displays consist
14. ceptual model without knowing what a device is to be used for it can appear mysterious and confusing Know that this is an apple peeler know oe an apple is placed on the prongs and as the handle is turned the apple rotates under the blade and now the structure is clear Produce a good conceptual model and no manual is necessary Photograph courtesy of Corbis Bettmann purpose a conceptual model In the case of the kitchen appliance the name alone is often sufficient to provide coherence That s an apple peeler Oh I see So the apple must fit here and these prongs go into the core holding the apple and this crank turmisi This cutting edge must be the peeler and this crank turns the apple in font of the blade And this is the blade that moves along the outside cutting off the skin Oh yes now I see It s obvious Even if you know what a tool is for unless you understand how it works its use is limited It s possible to use things without 176 Chapter 8 understanding by just following instructions This works until either something goes wrong or there is a need to do something unusual something not covered by the instructions In either case the result can be frustrating there is no hint of what to do next Once there is under standing it s possible to explain the problems and predict what to do It s possible to invent new applications and to make corrections when things go wrong With understanding com
15. consists mainly of improve ments in what has already existed These of course are important they are changing the fabric of everyday life and the structure of society and government But compared to the dramatic changes at the start of the twentieth century they seem more incremental than revolutionary To day we are amused by the statement made in 1899 by the Commissioner of the U S Office of Patents that everything that can be invented has been invented but given the remarkable list of accomplishments and discoveries in that era we should also feel sympathetic If the late 1800s and early 1900s was an era of dramatic revolution in technology it was also the era of increased complexity of life and of a regimented work style Henry Ford s assembly line philosophy Ford ism and Frederick Taylor s principles of scientific management Tay lorism specified work practices throughout the world They led to the dehumanization of work although this trend had started prior to Ford and Taylor in the textile factories of both England and New England Feeding clothing and entertaining the people of the world is a huge enterprise one in which the foot soldiers factory and field workers are often sacrificed For the steadily increasing middle class and the upper class it was a great time to be alive Today we are fond of making similar claims We live in interesting times Information technology has reached its prime or
16. d point of view even though it is designed and built by humans 168 Chapter 8 Early technology was not only difficult it was dangerous Missing fingers even limbs are still common among farmers construction workers and miners At the start of the industrial revolution hunger and poverty were prevalent Disease was everywhere and plagues could Kill entire communities The working conditions within many indus tries were hazardous and there was slight regard for safety that was the responsibility of the worker Clothes could be caught in machinery re sulting in death or serious injury It is only in recent times that we have started to care for the welfare of the workers and put the blame on the design or the work procedures rather than on the worker It is still common to hear managers say that if someone gets injured on the job that individual must have been doing something wrong This is the blame and train philosophy This philosophy makes the managers lives easier and it is one with which even the injured workers will often agree That was stupid of me they say shaking their heads How did I stick my finger into that fan blade the worker says I knew it was there I knew it was dangerous True but why was the fan blade designed so that a finger could be stuck into it Why was it located where the finger could reach Just because people are willing to blame themselves for their injuries does
17. een i chapter 5 there is no magical cure that will make everything all righ letting us proceed essentially as we are now doing What is the answe The most promising hope is a new process for product developmer that focuses upon human comprehension a human centered develoy ment process Read on
18. ent with that model What Makes Things Easy to Use When is something easy to use My studies convince me that even the most difficult of things becomes easy when users feel they are in control that they know what to do when to do it and what to expect from the device whenever they perform an operation in other words when they have acquired understanding What makes something understandable Technical knowledge is not required just functional What is critical is to have a good conceptual understanding of the device Few of us 174 Chapter 8 understand the technologies of the automobile radio or television yet we feel comfortable with these devices because each control has a known function we can tell when the device is working properly and we know what to do when there are problems We feel uncomfortable when we are out of control when we do not know how to respond or when our actions do not lead to the results we expect A feeling of control a good conceptual model and knowledge of what is happening are all critical to ease of use The controls must be recogniz able it must be easy to remember their function and Operation and they must provide immediate and continual feedback about the state of the system When is something difficult When the controls and actions seem arbitrary when the system can get itself into peculiar states peculiar in the sense that the person using it does not know what it is doing how it got
19. es a feeling of control Given a chance people are wonderfully good at making sense of the world People see faces and objects in clouds They see patterns in tea leaves They give explanations of people s behavior even people they don t know We human beings are sense makers making sense of the way we experience the world but only if there is something to go on some hints and clues as to what is happening and why When I encounter a new situation how do I know what to do I look listen and copy I try to understand what is happening I see if I can find anything that looks familiar and if I do then I ll perform the actions that work in the familiar situation Is it a new restaurant I have to decide whether I seat myself or whether I wait for someone to seat me If the latter I have to decide who it is that helps me where I should stand while waiting To answer these questions I look around and try to find clues If I m supposed to wait is there a place that looks like a waiting area Is there a table or stand that looks like it belongs to the head waiter or a host who will guide me to my seat or tell me how long I must wait I look for any clues I can find When I encounter a new piece of technology I do the same thing I look at it and try to see if anything looks familiar I look to see if there are any clear indications of what to do And when I do something that causes a reaction I try to understand why whatever I did led
20. esk No they are not The objects on my computer screen aren t at all like the real objects with which they share a name Metaphors are an at tempt to use one thing to represent another when the other is not the same But if it is not the same how can the metaphor help True where the properties of the metaphor and the new thing are closely related the metaphor helps in acquiring those properties But when they differ the metaphor can get in the way of learning it either provides the wrong model or it slows up acquisition of the correct one Basically those who espouse the use of metaphors are giving human centered development a bad name almost as bad as those who believe f bs Why Is Everything So Difficult to Use 181 in user friendly systems User friendly systems invariably aren t They are cloying annoying in your face systems that force the user through a sequence of steps whether or not these are appropriate whether or not the user is at a far more advanced level than the steps assume It is true that use of a metaphor is appropriate in the initial stages of learning But while those first stages are only there temporarily the metaphor is with us forever After those first few steps of learning the metaphor is guaranteed to get in the way because by the very nature of metaphor the thing being represented by the other isn t the same The result is conflict The window in the computer interface has a
21. f each control indicate 182 Chapter 8 something significant The displays and feedback can be precise and to the point explaining to the user what is going on why the actions are needed what they are for Good design is not necessarily self explanatory Some tasks are inherently too complex The notion that design can render anything intuitively obvious is false In fact intuition is simply a state of sub conscious knowledge that comes about after extended practice and ex perience With minor exceptions things that we call intuitive are simply skills that we have practiced for so many years that we no longer recall how difficult it was to learn them in the first place Skills such as using a pencil driving an automobile speaking and understanding lan guage reading and writing All these are intuitive to the skilled adult yet all took years to learn Difficult tasks will always have to be taught The trick is to ensure that the technology is not part of the difficulty Devices for complex tasks must of themselves be complex but they can still be easy to use if the devices are properly designed so that they fit naturally into the task When this is done learn the task and you know the device One goal is that each operation fit so elegantly within the structure of the task that it need be explained only once If users say Of course I see and never have to be told again there is success If users say Uh I guess
22. is people who are found to be superior machines deficient The Origins of Technological Difficulty Others have speculated on why today s technology seems so much more difficult and complex than that of earlier years One author thought it was due to covering up the working parts He suggested that If the discovery of electricity changed the face of the earth it also altered the look of every tool appliance or piece of machinery that it touched Yo cannot see the workings of any electrical device All that mysterious stuff is placed within a housing of some sort out of reach out of sight and beyond control This 1905 chopper shows the way things used to be The works blades gears are all there for all the world to behold People had to know how things worked so when things stopped working they could be fixed There is much to be said for this idea but it isn t entirely true Many mechanical devices were difficult to use even though or perhaps be cause all of the moving parts were visible Electricity is not the culprit Difficulty seems to go hand in hand with technology from early me chanical devices through today s information based ones How long has technology been so difficult Perhaps forever The joint evils of poor manuals and overcomplexity resulting from creeping fea turism attacked the common farm tool the plough almost 500 years ago Where is the difficulty in something as simple as a plough The pr
23. lephone When the telephone was first invented in the late 1800s everyone knew it was important but no body knew why Every city in the United States will have to have one the pundits said The thought was that people would gather round the phone in the town square and listen to news and concerts Little did they realiz that it would change the fabric of business and home In the early days great concern was given to privacy to the question of who would be allowed to use the telephone One telephone company took the phone away from a hotel why it was allowing mere guests to use it What would happen the telephone company asked if anyone could simply call up anyone else Horrors Those early concerns were soon brushed away today they seem quaint But perhaps they were also correct The telephone today is abra sive and intrusive A caller has no way of knowing whether the person being called is busy or idle in a good mood or foul The person getting the phone call has no way of knowing if the message is important or a bother whether it will be a short conversation or a long one The telephone answering machine has improved life to some extent It allows us to decide whether we wish to answer The answering ma chine itself is a double edged technology one with an interesting his tory When it first appeared it was mainly used by business in particular small businesses without anyone who could answer the 166 Chap
24. n The tightmost slider sets the right margin That s a useful conceptual model I don t know how the word proces sor really works deep inside its intricate programming structures I don t know anything about all the gory programming details that cou ple the pointer movements to the part of the page where the action takes place Part of my conceptual model is that the action only takes place on the line or paragraph where the cursor is located unless I have highlighted a section of text in which case it applies to everything that is highlighted With this understanding I feel empowered to adjust the formatting of the page I am in control Notice how skillfully the graphi cal design conveys the model The most clever component is the vertical dotted line that appears only when the slider is activated It is really the vertical line that conveys the conceptual model Notice the rectangle that sits below the leftmost upward facing trian gle What role does it play Here the graphical design is deficient Click ing on either the triangle or the rectangle just beneath it provides the same visual result a vertical dotted line Moreover if I try moving the item whether I click on the rectangle or the triangle both move to gether as a single unit This implies that the rectangle has no function Could it be just a design element to distinguish that first triangle from the others A more careful examination shows that the outcome of moving
25. not mean they are correct to do so The new technologies are designed to be used by people ordinary people people who grow fatigued whose attention wanders whose mind is preoccupied It does no good to legislate against such properties of human nature It does no good to complain that if only workers would keep their minds focused on the task they would not be getting injured Everyone s mind wanders everyone daydreams gets fatigued workers and management alike Proper design takes this into account A great deal of effort is aimed at preventing analogous problems in machines Engineers and designers take account of metal fatigue and random electrical noise They need to do the same for human function ing It s not easy The blame and train philosophy seems deeply in grained within our consciousness in part a relic of the Fordism and Why Is Everything So Difficult to Use 169 Taylorism of the early 1900s This is a philosophy that avoids the true source of the problem badly designed technology badly designed procedures The dilemma has been with us a long time and suspect it will be with us yet for a long time This is yet another legacy of the era of scientific management where the human is treated as a machine and then found to be deficient Someday the values might change letting it be acknowledged that we are complementaty to machines When we evaluate human skills and abilities according to human values it
26. oblem was that those sixteenth century technologists kept adding features and adjustments There was a coulter to cut roots in front of the share and a mouldboard to deflect the sod as it was cut Sometimes there 170 Chapter 8 was a wheel depending upon the type of soil The curvature of the mouldboard was adjustable and it was also twisted The blade could be wood or iron covered The plough then had to be adjusted for the kind of soil the amount of water muddy versus dry soil the condition of the soil the amount of existing vegetation and the kind of plant being prepared for The real boom in difficulty came with the industrial revolution as continual improvements in farming mining manufacturing and transportation were introduced The late 1800s and early 1900s saw the emergence of the electrical industry starting with communications the telegraph stock ticker and telephone along with devices for light heat and power light bulbs heating devices and electric motors These moved into the home and office Today the phonograph the telephone and typewriter are considered simple not so when they were first introduced For example the earliest phonographs were completely mechanical driven by a hand crank and by the acoustic energy of the source The spring driven and the electric motor came later but they didn t neces sarily make the device simpler The phonograph took weeks to master and in the end led to the fail
27. ore complex inside Early radios used a simple cat s whiskers and earphones a metal contact the cat s whisker upon a germanium crystal With the intro duction of vacuum tubes the sets became much more powerful but required multiple controls to modulate the amplification level anc tuning of each stage Some required adjustment of filter bandwidth 172 Chapter 8 depending on what kind of signal was being received and how much background noise could be tolerated by the listener As the illustration at the opening to this chapter shows the instructions for operation of these early radios could be rather intimidating The user of early radios was expected to know the five fundamentals of radio reception inter cepting tuning detecting amplifying and reproducing Today s radios are trivial to use sometimes having only an on off switch a volume control and a set of buttons to choose the station The external simplic ity comes with a greatly increased internal complexity within the elec tronic circuits themselves a complexity that would astound the electrical engineers who worked on the early vacuum tube sets See figure 2 1 page 22 A similar cycle is followed by most technology The modern automo bile is simpler for the driver than ever before but the auto itself has greatly increased in complexity It has thousands of parts from several technologies mechanical hydraulic and electronic so many that
28. out the design is that I can experiment by moving each slider in turn and seeing what happens As a result I have formed a good conceptual What does it mean to understand how something works Del really have to understand automobile mechanics te drive my icar understand solid state physics and computer Figure 8 3 Microsoft Word s excellent conceptual model for adjusting margins the along with the triangular and rectangular sliders are clear indicators of margin adjust ments The ruler starts and ends at the edge of the printed region of the document Moving the mouse pointer to the downward facing triangle and depressing the mouse button produces a vertical dotted line helping define us triangle asi indentation for the first line of a paragraph and also aiding the user in adjusting it t the desired value The difference between the rectangular slider and the upward pointing triangle is not so well indicated 178 Chapter 8 model of the role the sliders play in the composition of the page As soon as I move a slider a dotted vertical line drops down over the text confirming the conceptual model that the slider adjusts the location of the margins on the page as well as letting me see just where the slider is positioned relative to the existing text The leftmost slider sets the left margin The next slider over the upper slider sets the left indentation for the first line of each paragraph as shown in the illustratio
29. probably no single individual understands them all The modern air plane is simpler and safer for the pilots and passengers than those of only a few decades ago but it contains millions of parts that take hun dreds of designers to construct Even small devices have been modified in the years since their initial development for increased efficiency improved performance increased safety smaller size less power con sumption and less environmental impact The result is enhanced per formance and ease of use but increased internal complexity I once argued that modern technology is difficult to use because its operations are invisible Information is abstract conveyed by elec trons and voltage levels The workings of modern devices are hidden inside the sealed parts We are left to the mercy of whatever conceptual model the designer decides to impose upon us and the result is often confusion and misunderstanding In the old days I argued the user had a hope of figuring out how a thing worked by manipulating it and watching what moved Well I was wrong The difficulties with the plough with the mechanical phonograph and with other older tech nologies show that this explanation is too simplistic Some of those f 1 Why Is Everything So Difficult to Use 173 early mechanical devices were extremely difficult with such a variety of mechanisms that they were incomprehensible The first digital com puter was entirely mechanic
30. ter 8 phone and take messages when the intended recipient was not there When the first answering machines appeared in homes most callers considered them to be rude people were annoyed to get an automated response on a machine when what they wanted was a person Today at least in many countries of the world the answering machine is taken for granted In some places it is considered rude not to have such a machine for then it isn t possible to leave messages when the person is either away from the phone or otherwise not answering Not only that but there are times when we simply wish to convey a short message without a lengthy conversation In this case we sometimes prefer just to get the answering machine How many times have you called someone and been annoyed to get a person rather than the ma chine especially when the person who answered the phone was not the one for whom the message was intended Let me call back and just leave a message on the machine you request of the person The transition of the answering machine from that of a rude incon siderate technology to the class of an essential convenient one is simi lar to the path followed by other devices Most technologies go through a cycle of initial rejection followed by experimentation and transforma tion as their true value is discovered The original answering machines played aloud the caller s voice as their message was being recorded I don t know if this
31. there or how to recover When there is a lack of understanding Understanding comes about when the system presents a clear concep tual model of itself making the possible actions apparent I called this state knowledge in the world when the world itself helps tell you what to do so no instructions no courses no manuals are necessary A solid wall tells you that you can t walk in that direction A door signals passage A properly constructed door even specifies whether it is to be pushed or pulled slid or lifted by the construction of its handles no labels or words required If you have to add a sign that says push or pull then this indicates that the door is not as simple as is possible its design is faulty Did you ever look at an unfamiliar tool or appliance and try to figure out what it was for and how it might work Usually the tool makes no sense Once you are told what it is used for however the previously puzzling construction of weird parts suddenly all fit together wonder fully At first the device presents itself as a bunch of apparently unre lated affordances This part can stick into something this part permits turning this part cuts But any object has a large number of affordances and an assemblage of parts has a huge number of alternative combina tions What is lacking is a cohesive story to fit them together for some scene ica inna Why Is Everything So Difficult to Use 175 a con
32. times when they attempt to move the left margin they change both the first line and the others sometimes only the others Will they be astute enough to recognize that the exact region of the slider they touched was what mattered the triangle or the rectangle beneath it Details matter especially when they impact the user s conceptual model and thereby the user s understanding The basic principle is this Start with a simple cohesive conceptual model and use it to direct all aspects of the design The details of imple mentation then flow naturally from the conceptual model To summarize a conceptual model is a story It doesn t have to discuss the actual mechanisms of the operation But it does have to pull oe actions together into a coherent whole that allows the user to feel ii control to feel there is a reason for the way things are structured to fee that when necessary it s possible to invent special variations to get out of trouble and in general feel mastery over the device The job of creating a good conceptual model is in the hands of the designer The model has to be coherent understandable and sut ficiently cohesive that it covers the major operations of the system Iti successful if the users can tell a story can explain to others how it al works It is successful if the users can then use the system in ways the de velopers never imagined Above all the user should be able to discove 180 Chapter 8 and
33. ure of the first generation of products Early users were asked to persevere If the first trial is not pleasing try it again and persevere at it stick to it Give the Phonograph a thorough trial of two weeks 6 Why should we spend time and money to learn telegraphy shorthand and typewriting and then have an idea that no time is required to learn the Phono graph the most delicate of all and one of the most useful The use of the Phonograph must be learned the same as anything else One needs a few days to learn everything about it and only a few weeks practice to acquire all the dexterity in its use To be fair the difficulty was to enable the phonograph both to record and play back sound but even playing back was a trial The point is that difficulty in the use of our technology has been with us for a long time Many of those early technologies were difficult and worse dangerous i f E Why Is Everything So Difficult to Use 171 The steam engine kept exploding with numerous deaths and govern ment investigations before it was tamed The automobile was viewed with alarm Drivers had either to be expert mechanics or be accompa nied by one Vehicles were difficult to control and governments passed restrictive legislation The telephone was a special technology that took time to master and for that matter to figure out what it was good for Robert Pool argues that difficulty
Download Pdf Manuals
Related Search